Tag: oxidative phosphorylation

Questions Related to oxidative phosphorylation

Two copper centers are component of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Cytochrome $bc _1$ complex

  2. NADH dehydrogenase complex

  3. ATP synthase complex

  4. Cytochrome c oxidase complex

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Correct Option: A
Explanation:

Option 'A' is correct.


Two copper centres two $W _a$ and $W _b$ are component of cytochrome $bc$, complex. $W _a$ contains two copper cone which are linked by two bridging cysteine residue, whereas $W _b$ is linked by there histidine residues.

How any molecules of water should be photolysed to form a $NADPH 2$ molecule ________.

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. 4

  2. 2

  3. 6

  4. 1

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Correct Option: A

In which of the following phosphorylation in absent?

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Glycolysis

  2. Kreb cycle

  3. $C _4$ cycle

  4. ETS

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Correct Option: C
Explanation:

$C _4$ cycle or the Hatch-Slack pathway is a photosynthetic process in some plants. It is the first step in extracting carbon from carbon dioxide to be able to use it in sugar and other biomolecules. $C _4$ plants do not undergo phosphorylation due to their special mechanism to increase the $CO _2$ level for enzyme binding.

So, the correct answer is '$C _4$ cycle'.

Which of the following is a coenzyme?

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. NAD

  2. NADP

  3. FAD

  4. All the above

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Correct Option: D
Explanation:

Co-enzymes are organic compounds, are bound to the the enzyme to make the enzyme catalytically active, but their association with the enzyme is only transient, usually occurring during the course of catalysis. Co-enzymes serve as co-factors in a number of different enzyme catalyzed reactions. The essential chemical components of many coenzymes are vitamins, e.g., coenzyme nicotinamide adenine dinucleotide (NAD) and NADP contain the vitamin niacin; flavin adenine dinucleotide (FAD) is derived from riboflavin vitamin.

All of the following is true about oxidative phosphorylation, except

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. It occurs in the inner membrane of the mitochondrion.

  2. It involves O$ _2$ as the final electron acceptor.

  3. It produces 2 ATPs for each FADH$ _2$.

  4. It can occur under anaerobic conditions.

  5. It involves a proton gradient.

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Correct Option: D
Explanation:

Oxidative phosphorylation is an ATP generating process, which takes place in the inner membrane of mitochondria of aerobic organisms. In a generic sense, this process generates ATP via transferring electrons from $FADH _2$ or NADH via a series of complex carriers. Oxygen is a vital constituent of this process for its role as the final electron acceptor. Therefore, oxidative phosphorylation cannot take place in absence of oxygen. Hence, the correct answer is (D).

Which of the following is produced by oxidative phosphorylation?

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Oxygen and water

  2. NADH and ATP

  3. Pyruvate and NADPH

  4. Water and ATP

  5. Oxygen and NADH

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Correct Option: D
Explanation:

The metabolic process of releasing energy from food can be termed as oxidative phosphorylation. It occurs in the mitochondria of eukaryotic cell. In this process, the electrons are transported through different carriers ultimately to the oxygen molecule. these electrons reduce oxygen to form water and release energy which converts ADP to ATP. 

ATP is produced by oxidative phosphorylation in

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Glycolysis.

  2. Krebs cycle.

  3. Chemiosmosis.

  4. B and C only.

  5. A, B and C.

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Correct Option: C
Explanation:
Glycolysis and Kreb's cycle form total 4 ATPs by substrate level phosphorylation wherein the direct transfer of phosphate group to ADP or GDP during chemical reactions leads to the synthesis of ATP/GTP. Oxidative phosphorylation is the process wherein oxidation of reducing equivalent generate energy to drive ATP synthesis. Chemiosmosis includes the use of proton gradient generated across the inner mitochondrial membrane, during transfer of electrons from NADH and FADH$ _2$ to O$ _2$, to drive ATP synthesis. During chemiosmosis, 10 molecules of NADH power synthesis of 10*3 = 30 ATP while 2 molecules of FADH$ _2$ power synthesis of 2*2 = 4 ATP.
Thus, the correct answer is option C.

Electron carriers such as nicotinamide adenine dinucleotide (NAD) are used in energy capturing processes such as photosynthesis and respiration. They play a central role in the redox reactions that occur at the time of energy harvest from the carbon source.
What is the function of an oxidizing agent?

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Molecules that donate electrons.

  2. A molecule that becomes oxidized.

  3. A molecule that gains electrons.

  4. Molecules that combines with oxygen.

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Correct Option: C
Explanation:

NAD$^+$ accepts electrons/H$^+$ released by water.

So, the correct answer is 'A molecule that gains electrons'

Enzymes required for phosphorylation are located in .......... of chloroplast.

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Peristromium

  2. Plastidome

  3. Stroma

  4. Quantosome

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Correct Option: C
Explanation:

In chloroplast, the space enclosed by the inner membrane is called the stroma. It is colorless and homogeneous fluid. Phosphorylation is the process of addition of a phosphate group to ADP. The process of non-cyclic photophosphorylation takes place in the stroma lamellae with the help of enzymes present in it. Thus, the correct answer is option C. 

Centre of phosphorylation is

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Ribosome

  2. Oxisome

  3. Peroxisome

  4. Spherosome.

Show answer
Correct Option: B
Explanation:

  • Oxidative phosphorylation refers to the process by which ATP molecules (energy currency) are produced in the mitochondria.
  • ATP is produced by the transfer of electrons from NADH or FADH2 to oxygen molecule with the help of electron carriers.
  • Oxysomes or F0-F1 particles refers to small round structures present within the folds of the cristae of the inner mitochondrial membrane.
  • F0 and F1 particles are found in the inner mitochondrial region and are attached to the cristae and help in ATP production and oxidation.
So, the correct answer is 'Oxisome'.